Insect Microfluidics: Hearing and Breathing While Tiny
Insects have evolved to handle fluids using strategies that vary significantly from those used by larger animals since, by virtue of their size, they interact with fluids in the microscale regime, where surface forces dominate. Here we discuss two examples from insect microfluidics: flow actuation in insect respiration, and the amplification of acoustic sound localization cues in a parasitoid fly. We review behavioral data and present the mathematical, computational, and microfluidic device models we have developed to represent idealized versions of these systems that retain the salient features. In both examples, the insects appear to make use of finely tuned structural and material properties in the organs that come into contact with the fluids in question. In the case of the fly, we show that a tympanal asymmetry of just 5% may lead to order-of-magnitude gains in its hearing abilities.